In cutting tools for grooving, turning or parting-off, and in cutting tools for rotary slot cutting, a cutting insert is often retained in an insert pocket between two generally opposing jaws. In these tools, chips flowing from the cutting insert's cutting edge along its rake surface during a cutting operation may engage the jaw adjacent the rake surface and subject it to considerable abrasive wear. This disadvantageous effect will in time reduce the jaw's ability to retain the cutting insert within the insert pocket.
One solution which significantly overcomes this disadvantageous effect is disclosed in U.S. Pat. No. 5,947,648 to Friedman et al. A tool holder includes a holder blade having an upper jaw and a base jaw wherein the upper jaw is fitted with an exchangeable head material shield insert for protecting it against wear. However, this introduces additional maintenance of the tool.
Another solution is disclosed in U.S. Pat. No. 7,090,443 B2 to Hecht. A cutting insert is retained in an insert pocket of a cutting tool by means of a retaining screw. The lower surface of the cutting insert comprises a pair of insert lower faces which extend rearwardly from the forward surface at an external non-acute insert lower angle to each other. The lower abutment surface of the insert pocket comprises a pair of lower faces which extend forwardly from the pocket recess at an internal holder lower angle to each other. The internal holder lower angle is equal or slightly smaller than the external insert lower angle.
Lateral stability of the cutting insert relative to the insert holder is provided by the lower and rear surfaces of the cutting insert having generally V-shape concave (or convex) cross sections, which mate corresponding generally V-shape convex (or concave) cross sections of the lower and rear abutment surfaces of the insert pocket.
There are several types of shaving tools in the market. A first kind of shaving tool is made of a solid block of HSS that is retained by a dedicated mechanism. The hardness and tool life of such a tool may be limited for some applications.
Another kind of shaving tool is made of a solid block of cemented carbide that is retained by a dedicated mechanism. Despite the advantages of using a cemented carbide block, it is relatively expensive and requires re-grinding after becoming worn.
Another kind of shaving tool comprises a cemented carbide flat plate that is retained in position by a clamping arm. Such kind of tool requires a time consuming process of alignment in position. Furthermore, after becoming worn, the plate has to be re-grinded and than be re-aligned in its position.